1. Field of the Invention
This invention relates to halofluorinated monomers; and more particularly to a method for making halofluorinated monomers.
2. Description of the Prior Art
The production of optical waveguiding structures by photocuring commercially available multifunctional acrylates containing C, H, O, and N atoms is well known. Such structures, however, exhibit high optical loss at the near infrared region due to the inherent absorption of the C--H bond. Replacing the C--H by C--F bonds results in reduced optical loss, but the refractive index of the resulting photopolymer becomes undesirably low. One approach to alleviate this problem has been the replacement of a portion of the fluorine atoms of the fluoroalkylene moiety with heavier halogen atoms such as chlorine and bromine, both of which are known to increase refractive indices.
In many instances, the processes for making the foregoing halogen-substituted fluorinated acrylates can be quite cumbersome. It would therefore be desirable to provide an improved process for making modified fluorinated monomers for interconnect applications which can be photocured to form optical waveguide structures possessing low optical loss and having increased adhesion. Additionally, it would be desirable if such modified fluorinated monomers would have a refractive index value approaching that of traditional optical fibers.